a Issues for the years Sept. 1971-May 1980 also called v. 29-37. Issues for the year Sept. 1980-May 1981 also have randomly supplied volumes and numbering. Issues for the years Sept. 1981-Sept. 1990 also called v. 12-v. 19. Vol. 19 enumeration used for both 1988/1989 and for 1989/1990.